Balanced relay



June 17, 1947.

R. s. CURRY, JR., Erm.v 2,422,396

BALAncED naw! Filed larcn 2, 1943 2 sheets-sheet 1 June 17,1194?.l R. s. c'umgJR., :TAL

AmmcFb` RELAY Filed arch 2, 1943 2 Sheets-Sheet 2 l I I I I I I' 7///////////A LA Patented June `17, 1947 BALANCE!) RELAY Robert S. Curry, Jr., Baldwin, John H. Homan,

Tuckahoe, and August C. Kircher and Herbert Wimker, Jackson Heights, N. Y., assignon, by menne assignments. to AIM Control Company, Inc., New York, N. Y., a corporation ot New York Application March 2. 1943, Serial No. 477,750

Claims.

This invention is directed to relays, more particularly, to relays of the balanced type. It is among the objects oi the present invention to provide a balanced relay wherein slight changes of current passing through a pair of coils is adapted to make or break circuits and to maintain such circuits ilrmly against vibration.

It isalso among the objects of the present invention to provide a structure wherein the movements of the amature oi the relay will give a wiping action on the contacts. closing a circuit ilrmly so as to avoid chattering and resist exter-y nal vibration without losing the contact.

It is further among the objects oi' the present inventionto provide a structure which is responsive to extremely small changes of currents and has a delicate balance, but which is protected against outside forces so that the relay will withstand severe service.y

It is still further among the objects of the present invention to provide a relay structure which is adapted for large quantity production, which may be assembled in several units. which lends itself to ready replacement of parts, wherein the various terminals are readily accessible, and

which may be secured to various types of supports.

The novel construction of the present invention is illustrated in the drawings constituting a part hereof and in which like reference characters indicate like parts, wherein:

Fig. 1 is a side elevational view of the new relay with the lower supporting member bent out of line to better illustrate the structure;

Fig. 2 is an end elevational view thereofi Fig. 3 is a top plan view thereof;

Fig.v 4 isa bottom plan view thereof;

Fig. 5 is a vertical cross-sectional view taken along the line 5-5 of Fig. 1:

' Fig. 6 is an enlarged fragmentary cross-sectional view of the contact making members and associated parts;

Fig. 7 is a view taken along the line 1--1 of Fig. 6, some parts being shown in cross-section for cleamess; and

the heads of screws 6. Nuts I4 mounted on the ends o! plate il provide means for securing the same to a suitable base. Because base I and plate i0 are not connected except at a central point. ii the surface on which the relay is to be mounted is irregular, the plate i0 may be bent in any desired manner so as to be capable ot ilrm attach- 1ment to the support. This is indicated at the lower left side oi' Fig. 1 wherein the plate is shown bent to accommodate an irregular surface.

Above the coils is provided a metal contact support having the opposed sides I5 thereof bent .downwardly to form ears embracing bar 4, and

thin metal plates I1 are placed on the outside thereof. It is secured to bar 4 by screws Il. By this construction an uninterrupted magnetic path is provided so that ilux may readily ilow through each core 5, base I, bar 4 and the armature oi the relay. The armature I9 overlies both of the coils and has a pair oi' ears 20 formed along the central portion of the sides thereof, said ears accommodating a pin 2| which is held in ears II. vAn insulating plate 22 is carried by the contact support I5. Secured to the upper side oi the plate 22 is an insulating block consisting oi' a plurality of insulating plates or laminae 24, 25, 2i. 21, 28 and 29 oi diiierent lengths, widths and thicknesses forming longitudinal recesses. The plates 24, 25 and 25 are approximately the same length as the plate 22 while the plate 25 is of less width than the plates 24 and 25 to form a longitudinal recess in which is arranged a spring metal contact piece 30 having its ends projecting beyond the ends ot the plates 24. 25 and 26 and being provided at its ends with terminal Abuttons 3l overlying the ends of the armature I9. Also. in the recess is provided a terminal member I2 underlying the contact piece I0 and projecting beyond the face of the insulating block. The plate 21 is of the same width as, but slightly longer than the plates 24 and 25 while the plate 25 is of the same length as the plate 21 but of less width to form a longitudinal recess in which is arranged a pair of longitudinally spaced contact l pieces 3l having their ends projecting beyond the Fig. 8 is a fragmentary side elevation showing a modication.

a There is provided a metal base I having mounted thereon a pair of coils 2 and I with a metal bar 4 of magnetic material placed between -said coils. Each of the coils is provided with a eentral core 5, and screws 8 passing through base I hold the coils in position with their axes parallel. The base has a pair oi' ears 1 and 8 bent upwardly and embracing the sides o! bar 4, and screws 9 ilrmly secure the same to bar 4.

A supporting plate Il below base I is spaced therefrom by spacer i I and is secured to said base and bar 4 by screws I2. Plate I0 has apair oi.'

ends of the plate 21 and each contact piece having a contact button 24 in co-operative relation with a terminal button Il. Also, in the recess is provided a terminal member 35 underlying each contact piece 88 and projecting beyond the lace of the insulating block. The plate 29 is of` the same width as .the plate 21 and is of suiilcient length to overlie the ends of the contact pieces 3l while the relative dimensions and positions are Vsuch that a space intervenes between the plate `2l and the buttons I4. On the plate 2l is placed a metal protector 20 of stiil' material and the several metallic and insulating members are held together as a unit by screws. 31.

openings' il suiiiciently large to t loosely over 60 The contact piece is biased so that its terminal buttons 3l engage the ends of the armature I9 and by spring pressure hold the same in adjusted position. Also. the contact pieces 33 are biased toward the armature.

Each of the ends of armaturel Il is provided with an upwardly extending member 38 ,von the outer face of which is held threaded insulating member It. Said member is provided with a pair of semi-cylindrical recesses 4B in which the threads are located. A covering member 4i also has a pair of recesses 42 provided with comple-v mentary portions. of the threads which are formed in recesses 4l. An adjusting screw 43 is held in the opening formed by recesses 40 and 42 and carries in the head thereof a contacter 44 of insulating material. A set screw 4l holds the assembly in iixed position, as shown in Fig. 1. While in Fig. 7 only one screw 45 is illustrated and in the drawings only one set of contacts is shown, because of the construction it is possible to introduce an additional contact piece like Il parallel thereto. and insert an additional number of screws 43 and all associated parts so as to control four circuits instead of two, as shown and described.

The plate 22 has two pairs of terminal members 4I and 41. Connections 48 are made from the coil 2 to the terminal members 46 and similar connections 43 are made from the coil 3 to the terminal members 41. 'I'he free ends 5d of said terminal members provide means for attaching the coils to a suitable control circuit. As shown in Fig. 8, a transparent shield of suitable insulating material is supported in position to enclose the contacts 3| and 34. 'I'he shield 61| is held in place by a screw 52 passing therethrough into the metal plate Il.

In the operation of the device current from control circuits is caused to iiow through coils 2 and 3. When the relay is in inoperative position, the magnetic ilelds set up in the coils are equal and the magnetic force holds the armature in neutral adjusted position, as shown in Fig. l. Because of the balancing action of spring contact piece 30 and the force of the magnetic ileld the relay is held in balanced position so rmly that even severe vibration on the outside or application of blows, will not close the circuits. If, however, the magnetic ilelds set up by coils 2 and 3 are unbalanced even by a small amount of current change, a positive force is exerted, pulling armature I8 on one side or the other, thereby closing the circuit on the opposite side. Referring more particularly to Fig. 6, when the end of armature I9 is caused to move upwardly, button 3| being in contact with contacter 44, contact is made with button I4. Movement continues and Vbecause button J4 moves further, a rubbing or wiping action takes place between buttons ll and 34, thus insuring good electrical contact. When button 34 is in iirm contact with plate 29, a rm electrical contact is made. In this position even severe vibration is ineffective to loosen a contact or open the circuit.

Even though the operating elements of the balanced relay are in themselves of delicate construction and light in weight, the relay as a whole is very sturdy. Because of the double base and the heavy metal bar on the top of the relay, and because the terminals are within the general area of the relay and the delicate contacts are centrally. located within the relay, the latter may be subjected to extremely severe conditions without damage to the delicate elements. This is of extreme importance particularly where the retothe assembly by the use oi a few screws. Prom thisitwillbeseenthatinthemanufactureof the relay it is possible to make several sub-assemblies bly specialised labor whereby economy in production is obtained. I'he sub-assemblies may then be easily united to complete the relay.

Although we have described our invention set- 'ung forth a. single embodiment thereof. said embodiment was described for purposes of illustration only and it is not to be considered as limiting the invention. Those skilled in the art will readily appreciate that various details of construction may be changed at will while adhering to the principles set forth herein. The forms of the several members may be changed, as is well known. andthe materials used may be other than Ythose herein described. Therefore, the inventionistobebroadlyconstruedandnottobe limited except by the character of the claims appended hereto.

What we claim is:

l. A balanced relay comprising a pair of magnetic coils having their axes parallel and mounted on a common base of magnetic material, a bar of magneticmaterial between said coils and secured to said base, a balanced armature pivoted above and overlying said coils, an insulating member above said amature, a contact piece on one face thereof extending beyond the emk thereoi', and a pair of contact pieces on the other face cooperating with said nrst contact piece, said first contact piece being of spring metal and having its ends biased into engagement with the ends of said armature to balance the latter against vibration.

2. A balanced relay comprising a pair of magnetic coils having their axes parallel and mounted on a common base of magnetic material, a bar of magnetic material between said coils and secured to said base, a balanced armature pivoted above and overlying said coils, an insulating member above said armature, a contact piece on one face .thereof extending beyond the ends thereof, a pair 'of contact pieces on the other face cooperating with said rst contact piece, said rst contact piece being of spring metal and having its ends biased into engagement with the ends of said armature to balance the latter against vibration and each of the two remaining contact pieces being of spring metal having their ends biased toward said armature.

3. A balanced relay comprising a pair of magnetic coils having their axes parallel and mounted on a common base of magnetic material, a bar of magnetic material between said coils and secured to said base, a balanced armature pivoted above and overlying said coils, an insulating member above said armature, a contact piece on one face thereof extending beyond the ends thereof, a pair of contact pieces on the other face cooperating with said first contact piece, insulating elements covering said pieces, said ilrst contact piece being of spring metal having its ends biased into engagement with the ends of said armature to balance the latter against vibration and a contact supporting member secured to said bar, said insulating member and elements and said contact pieces being secured to said bar.

4. A balanced relay comprising a pair of magnetic coils having their axes parallel and mounted on a common base of magnetic material, a

Y pivoted balanced armature above and overlying said coils, an insulating member above said armature, a contact piece on one face thereof extending beyond the ends thereof, and a pair of contact pieces on the other face co-operating with said rst contact piece, said rst contact piece being of spring metal and having its ends biased into engagement with the ends of said armature to balance the latter against vibration. 5. A relay according to claim 4 characterized by each of the two remaining contact pieces being of spring metal and having their ends biased toward said armature.

' ROBERT S. CURRY, J R.

JOHN H. HORMAN. AUGUST C. KIRCHER. HERBERT WINSKER..

REFERENCES CITED The following references are of record in the le of this patent:

y UNITED STATES PATENTS Number Name Date 987,192 Turbayne Mar. 21, 1911 1,281,392 Kelly Oct. 15,1918 1,987,887 Ashworth et al Jan. 1.5, 1935 686,272 Dunbar Nov. 12, 1901 752,613 Carliss Feb. 16, '1904 1,165,098 Herr Dec. 21, 1915 514,398 Wiley Feb. 6, 1894 754,689 Pearne et al Mar. 15, 1904 799,016 Schwarze Sept. 6, 1905 l 959,787 Nicholson May 31, 1910 650,915 Scribner et al June 5, 1900 815,822 Herman Mar. 20, 1906 2,312,902 Hickman et al Mai'. 2, 1943 FOREIGN' PATENTS Number Country Date Germany Sept. 22, 1932 

